Trihydric alcohol derivatives

ABSTRACT

Certain novel trihydric alcohol derivatives, useful as herbicides and fungicides.

United States Patent Isaac et a1.

TRIHYDRIC ALCOHOL DERIVATIVES lnventors; Eirlys R. Isaac. Sittingbournc;

Michael D. Barker, Maidstune. both of England Assignee: Shell Oil Company, Houston. Tex.

Filed: Aug. 28. 1973 Appl, No; 392,394

Related US. Application Data Continuation of Ser. No. 74.505. Sept 22. 1971). abandoned.

Foreign Application Priority Data Sept, 23. 1969 United Kingdom 467-15/69 US. Cl. 260/3403; 260/3401; 260/4106. 260/488 .1; 260/488 CD; 260/635 H; 260/611 1 1 Nov. 11, 1975 Int. Cl. C07D 317/22 Field of Search 260/3407. 340.9

References Cited UNITED STATES PATENTS 1644.432 2/1973 Mine et a1 260/3409 3.753.678 8/1973 Yuung et a1 .1 36111340.?

FOREIGN PATENTS 0R APPLlCATlONS 15tI7A4-l 11/1967 France 260/340] 9 Claims, N0 Drawings polymethylene group,

TRIHYDRIC ALCOHOL DERIVATIVES This is a continuation of application Ser. No. 74,505, filed Sept. 22, 1970, and now abandoned.

BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION A new series of trihydric alcohol derivatives being at least partially etherified and/or esterified and wherein the three oxy (O) oxygen atoms of the alcohol chain are bonded to different carbon atoms, the carbon atom to which the central oxygen atom is attached being tertiary in character have been discovered. These novel compounds have shown high herbicidal activity in the control of certain economically important grass weed species and have proven effective in the control of certain fungal diseases.

This invention, accordingly, is a new series of trihydric alcohol derivatives being at least partially etherifled and/or esterified and wherein the three oxy (O) oxygen atoms of the alcohol chain are bonded to different carbon atoms, the carbon atom to which the central oxygen atom is attached being tertiary in character, their use as herbicides and fungicides, and pesticidal formulations containing them.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The novel compounds of this invention can be described by the general formula:

CH -CY,

R-C-OY, (I)

wherein R represents an alkyl group of 1-6 carbon atoms, suitably methyl, ethyl, propyl or hexyl; and

Y, and Y together represent an optionally substituted methylene group of the formula:

c (II) wherein R and R, each individually represents a hydrogen atom, an optionally substituted alkyl group particularly methyl, benzyl, ethyl, phenylethyl or butyl, a phenyl group optionally substituted by one or more halogen, especially chlorine atoms or by an alkyl group, for example methyl, or R and R together represent a particularly tetramethylene, pentamethylene or hexamethylene; and Y; represents an aryl group, particularly phenyl, an aralkyl group, particularly a benzyl group optionally substituted in the benzene ring by one or more fluorine or chlorine atoms or by a methyl or phenyl group.

By reason of their high level of biological activity the following compounds are particularly preferred:

4-benzyloxymethyl-2,2-dimethyl-4-n-propyl-l ,3- dioxolane 4-benzyloxymethyl-2,2-dimethyl-4-ethyl-l ,3-dioxolane 4-benzyloxymethyl-4-methyl-l ,3dioxolane-2- spirocyclohexane It will be appreciated that many of the 2-alkyl glycerol derivatives of the invention may exhibit geometrical and/or optical isomerism. The individual isomers of these compounds together with isomeric mixtures thereof are included within the scope of the present invention.

The compounds of formula I] are prepared by reacting the corresponding diol with a carbonyl compound of the formula:

or an acetal or ketal derived from such a carbonyl compound, in the presence of an acid, suitably an inorganic acid such as hydrochloric acid or an arylsulphonic acid such as p-toluene sulphonic acid. The reaction is preferably carried out in an aromatic hydrocarbon, for example benzene or toluene, as solvent.

As mentioned above the trihydric alcohol derivatives of the invention exhibit herbicidal and plant growth regulant properties and the invention therefore includes biologically active compositions comprising a carrier or a surface active agent, or both a carrier and a surface active agent, and as active ingredient at least one trihydric alcohol derivative of the invention.

The term carrier as used herein means a material, which may be inorganic or organic and of synthetic or natural origin, with which the active compound is mixed or formulated to facilitate its application to the plant seed, soil or other object to be treated, or its storage, transport or handling. The carrier may be a solid or a fluid. Any of the material usually applied in formulating pesticides may be used as carrier.

Suitable solid carriers are natural and synthetic clays and silicates, for example natural silicas such as diatomaceous earths; magnesium silicates, for example, talcs; magnesiusm aluminum silicates, for example, attapulgites and vermiculites; aluminum silicates, for example, kaolinites, montmorillinites and micas; calcium carbonates; calcium sulphate; synthetic hydrated silicon oxides and synthetic calcium or aluminum silicates; elements such as for examle, carbon and sulphur; natural and synthetic resins such as for example coumarone resins, polyvinyl chloride and styrene polymers and copolymers; solid polychlorophenols; bitumen; waxes such as for example, beeswax, paraffin wax, and chlorinated mineral waxes, solid fertilizers, for example superphosphonates.

Examples of suitable fluid carriers are water, alcohols, such as, for example, isopropanol, glycols; ketones, such as for example, acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethers; aromatic hydrocarbons such as, for example, benzene, toluene and xylene; petroleum fractions such as, for example, kerosene, light mineral oils; chlorinated hydrocarbons such as, for example, carbon tetrachloride, perchloroethylene, trichloroethane, including liquefied normally vaporous gaseous compounds. Mixtures of different liquids are often suitable.

The surface-active agent may be an emulsifying agent or a dispersing agent or a wetting agent; it may be nonionic or ionic. Any of the surface-active agents usually applied in formulating herbicides or insecticides may be used. Examples of suitable surface-active agents are the sodium or calcium salts of polyacrylic acids and lignin sulphonic acids; the condensation products of fatty acids or aliphatic amines or amides containing at least 12 carbon atoms in the molecule with ethtyl oxide and- /or propylene oxide; fatty acid esters of glycerol, sorbitan, sucrose or pentaerythritol; condensates of these with ethylene oxide and/or propylene oxide; condensation products of fatty alcohols or alkyl phenols, for example, p-octylphenol or p-octylcresol, with ethylene oxide and/or propylene oxide; sulphates or sulphonates of these condensation products; alkali or alkaline earth metal salts, preferably sodium salts, of sulphuric or sulphonic acid esters containing at least 10 carbon atoms in the molecule, for example, sodium lauryl sulphate, sodium secondary alkyl sulphates, sodium salts of sulphonated castor oil, and sodium alkylaryl sulphonates such as sodium dodecylbenzene sulphonate; and polymers of ethylene oxide and copolymers of ethylene oxide and propylene oxide.

The compositions of the invention may be formulated as wettable powders, dusts, granules, solutions, emulsifiable concentrates, emulsions, suspension concentrates and aerosols. Wettable powders are usually compounded to contain 25, 50 or 75% w of toxicant and usually contain, in addition to solid carrier, 3l0% w of a dispersing agent and, where necessary, Ol% w of stabilizer(s) and/or additives such as penetrants or stickers. Dusts are usually formulated as a dust concentrate having a similar composition to that of a wettable powder but without a dispersant, and are diluted in the field with further solid carrier to give a composition usually containing k l0% w of toxicant. Granules are usually prepared to have a size between and 100 BS mesh, and may be manufactured by agglomeration or impregnation techniques. Generally, granules will contain 1% 25% w toxicant and 0l0% w of additives such as stabilizers, slow release modifiers and binding agents. Emulsifiable concentrates usually contain, in addition to the solvent and, when necessary, co-solvent, 10-50% w/v toxicant, 2-20 w/v substantially and (Ii-% w/v of appropriate additives such as stabilers, penetrants and corrosion inhibitors. Suspension concentrates are compounded so as to obtain a stable, non-sedimenting, flowable product and usually contain l075% w toxicant, 0.5l5% w dispersing agents, 01-10% w of suspending agents such as protective colloids and thixotropic agents, Ol0% w of appropriate additives such as defoamers, corrosion inhibitors, stabilizers, penetrants and stickers, and as carrier, water or an organic liquid in which the toxicant is substantially insoluble; certain organic solids or inorganic salts may be dissolved in the carrier to assist in preventing sedimentation or as antifreeze agents for water.

The compositions of the invention may contain other ingredients, for example, protective colloids such as gelatin, glue, casein, gums, cellulose ethers, and polyvinyl alcohol; thixotropic agents, e.g., bentonites, sodium polyphosphates; stabilizers such as ethylene diamine tetra-acetic acids, urea, triphenyl phosphate; and stickers, for example non-volatile oils.

Aqueous dispersion and emulsions, for example, compositions obtained by diluting a wettable powder or 4 an emulsifiable concentrate according to the invention with water, also lie within the scope of the present invention. The said emulsions may be of the water-in-oil or of the oil-in-water type, and may have a thick mayonnaise-like consistency.

The trihydric alcohol derivatives of the present invention are of interest as herbicides and particularly as selective herbicides for pre-emergence application to control grass weeds. The invention includes therefore within its scope a method of protecting crops at a locus from composition by grass weeds which comprises applying to the locus a trihydric alcohol derivative or composition of the invention.

The compounds of the invention may be used in admixture with other herbicides and pesticides. in particular they may be mixed with active materials possessing pre-emergence activity against broad-leaf weeds to give herbicide combinations exhibiting broad-spectrum preemergence activity. Examples of such active materials are s-triazine derivatives such as 2,4-bis-(isopropylamino)-6-methylthio-s-triazine, or 2-chloro-4- ethylamino--isopropylamino-s-triazine, pyridazole derivatives such as 5-amino-4-chloro-2-phenylpyridaz- 3-one, or l,4-naphthaquinone derivatives.

The invention is further illustrated in the following Examples:

EXAMPLE I 4-Benzyloxymethyl-2,2,4-trimethyll ,3-dioxolane a. Preparation of Z-methylglycerol Methallyl alcohol (20.0g), alumina (20.0g) and tungstic acid (2.0g) in water ml) were heated to 60C and then hydrogen peroxide (31.6 ml of 30 w/v solution) was slowly added. During the addition the temperature of the mixture was maintained at 60C by cooling. When the addition was complete the mixture was maintained at 60C for a further hour and then at 95C for 2 hours. After cooling the mixture was filtered and the filtrate passed through two columns containing respectively Amberlite [RA 400 and Permutit Zeo- Carb. 225. The solvent was then removed from the solution to give the crude 2-methylglycerol which was not purified further.

b. Preparation of 4-hydroxymethyl-2,2,4-trimethyll ,3-dioxolane Z-Methylglycerol (50 g, prepared as in (21)), acetone ml), p-toluene sulphonic acid (1.5g) and petroleum ether (I50 ml, b.p. (4060C) were heated together for 24 hours at reflux temperature under two Vigreux columns (40 cm length each) and a Dean and Stark trap for removal of water. The reaction mixture was cooled and fused sodium acetate l .5 g) was added. The suspension was stirred at room temperature for 30 minutes and then filtered. The solvents were removed from the filtrate under reduced pressure and the residue was fractionally distilled. 4-hydroxymethyl-2,2,4- trimethyl-l ,3-dioxolane was obtained as a colorless liquid having a b.p. 77C at 12 mm Hg.

c. Preparation of 4-benzyloxymethyl-2,2,4-trimethyll ,3-dioxolane 4-Hydroxymethyl-2,2,4-trimethyl-l ,3-dioxolane (lOg, prepared as in (b)) was added dropwise to a stirred suspension of sodium hydride (3g, 50% dispersion in oil) in dry toluene (150 ml). When the addition was complete the solution was heated under reflux until no more hydrogen was evolved. Benzyl chloride (7.85g) was added to the refluxing solution over a period of l5 minutes. after which the solution was heated under reflux for a further 3 hours. The solution was then cooled, washed with water (3 X ml), dried and the solvent removed under reduced pressure. The residual oil was fractionally distilled to give the desired product as a colorless liquid having a b.p. 80C at 0.2 mm Hg.

Analysis EXAMPLE Ill Calculated for C H O: C 71.3; H 8.5% IO Found c 71.3; H 2.7% Following procedures similar to those of Example I and II further compounds were prepared. whose physical characteristics and analyses are given in Table 1.

Table 1 Boiling Compound Point Analysis ClmmHg 4-benzyloxymethyl-4-n-hexyl-2,2- Calculated for C H O C 74.5; H 9.8% dimethyl-l.3-dioxolane l24/0.3 Found C 74.5; H 9.9% 4-(4 chlorobenzyloxymethyl)-2,2,4- Calculated for C H o Cl C 62.0; H 7.0% trimethyl-l.3-dioxolane 94/0.l Found C 62.3; H 7.2% 4-(4-methylbenzyloxymethyl)-2,2,4- Calculated for C H O C 72.0; H 8.8% trimethylJJ-dioxolane 9ll0.3 Found C 71.6; H 8.8% 4-(3'methylbenzyloxymethyl)-2,2.4- Calculated for C H O C 72.0: H 8.8% trimethyl-l,3-dioxolane JO/0.3 Found C 72.0; H 8.6% 4-(3'.4'-dichlorobenzyloxymethyl)-2,2,4- Calculated for C H O CI, C 55.]; H 5.9% trimethyl-l .3-dioxolane l2l/0.3 Found C 55.9; H 6.0% 4-benzyloxymethyl-4-ethyl-2.2- Calculated for C ,-,H,,O, C 72.0; H 8.8% dimethyl-l ,3-dioxolane 96/03 Found C 72.2; H 9.0% 4-benzyloxymethyl-4-isopropyl-2.2- Calculated for C H o C 72.7; H 9.|% dimethyl-l,3 dioxolane 99/0.4 Found C 72.9; H 9.0% 4-benzyloxymethyl-Z-isobutyl-2.4- Calculated for C H O, C 73.4; H 9.4% dimethyl-l.3-dioxolane [03/03 Found C 73.3; H 9.4% 4-benzyloxymethyl-Z-ethyl-Z,4- Calculated for C l-I 0, C 72.0; H 8.3% dimethyl-l 3-dioxolane 9810.5 Found C 72.9; H 9. I)? 4-benzyloxymethyl-2,4-dimethyl- Calculated for c u o, C 76.5; H 7.4% 2-phenyl-l.3-dioxolane l25/0.l5 Found C 76.7; H 7.7% 4-(4'-fluorobenzyloxymethyl)-2,2,4- Calculated for C H O F C 66.l; H 7.5% trimethyl-LS-dioxolane 83/03 Found C 66.3; H 7.8% 4-(pyrid-4'-yl methoxy methyl)2,2,4- Calculated for C H NO C 65.8; H 8.0; N 5.9% trimethyl-l ,3-dioxolane 97/0.4 Found C 65.8; H 8.4; N 5.8% 4-(biphenyl-4'-yl methoxy methyl)-2,2 4- Calculated for C H O; C 76.9; H 7.7% trimethyl-lJ-dioxolane 142/015 Found C 76.7; H 8.0% 4-(cyclohexylmethoxymethyl)-2,2,4- 8889 Calculated for C .H O; C 69.4. H l0.7% trimethyI-L3-dioxolane /l.0 Found C 69.0; H l0.9% 4-benzyloxymethyl 4-methyl-2-phenyl-l,3- l36/0.l5 Calculated for C H O C 76.l; H 7.0% dioxolane Found C 76.4; H 7.4%

EXAMPLE EXAMPLE [V 3-Benzyloxymethyl-4-methyl-2-p-tolyl-l ,3-dioxolane 4-Benzyloxymethyl-2,2-dimethyl-4-n-propyl-l ,3-dioxolane a. Preparation of 2-n-propylglycerol Formaldehyde ml of 37-41% w solution) and dimethylamine hydrochloride (53g) were mixed to give a clear solution, to which was added slowly valericaldehyde (50g). The solution was maintained at 55C for 1 hour and then at 70C for 22-24 hours. The crude product was separated by steam distillation, dissolved in methanol (I00 ml) and reduced with sodium borohydride (525g) in aqueous methanol (45 ml) at 30-40C. When the reduction was complete, aqueous sodium hydroxide (120 ml of 13% solution) was added and the mixture heated at 80C for 1 hour. The solution was cooled and extracted with ether. The dried extracts were evaporated and the residual oil was dried with magnesium sulphate and fractionally distilled to yield Z-methyIenepentan-l-ol having a b.p. 6l"-63C at 15 mm Hg.

b. Following a series of reactions similar to those of Example I (a) (c) but using Z-methylenepentan-l-ol as starting material, the desired product was obtained Analysis Calculated for C,.H,,O, Found EXAMPLE V Following a procedure similar to that given in the previous Example, further compounds were prepared whose physical characteristics and analyses are set out in Table 2.

Table 2 hp. C/mmHg Compound or n Analysis 4-benzyloxymethyI-2-(4-chlorophenyl)- n l.5482 Calculated for C H O CI 1 C 67.8; H 5.9% 4-methyl-l.3-dioxolane Found C 68.0; H 6.3% 4-benzyloxymethyl-4-methyl-l.3- Calculated for C H C C 74.0; H 8.7)?

.lO2/0.t5 dioxolane2-spirocycl0hexane Found C 74.4; H 8.9% 4-benzyloxymethyI-Z-benzyl-2,4-dimethyl Calculated for c mp, C 77.0; H 7.7%

l30/0.l -l.3-dioxolane Found C 77.2; H 7.9)? 4-benzyloxymethyI-4-methyl-l.3- Calculated for C H O, C 73.4; H 8.4%

[07/02 dioxolane-2-spriocyclopentane Found 1 C 73.4; H 8.49? 4-benzyloxymethyl4-methyl-2-(2- Calculated for C H Q C 77.0; H 7 79;

l5I/O.I phenylethyl)-l.3dioxolane Found C 76.7; H 7.3% 4-benzyloxymethyl4-methyl-l,3- n l.5008 Calculated for C H O C 69.2; H 7.7% dioxolane Found C 69.6; H 7.7% 4-benzyloxymethyl-4-methyl-l,3- L506) Calculated for C H O L C 74.5; H 9.0% dioxolane-2-spirocycloheptane Found C 74.1: H 9.l71

EXAMPLE VI EXAMPLE IX 4-Benzyloxymethyl-2,4-dimethyl-l ,3-dioxolane Analysis Calculated for C H O Found EXAMPLE VII Following a procedure similar to that of Example VI the following compounds were also prepared:

4-benzyloxymethyl-Z-benzyl-4-methyl-1,3-dioxolane b.p. I34C at 0.2 mm Hg.

Analysis Calculated for C H O Found EXAMPLE Vlll 4-Phenoxymethy l-2,2,4-trimethyll ,3-dioxolane 4-Chloromethyl-2,2,4trimethyl-l ,3-dioxolane (5.0g) and sodium phenoxide (3.7g, prepared from phenol and sodium hydride) in dimethyl sulphoxide (90 ml) were heated together at 140C for 4 hours. The reaction mixture was diluted with water and the aqueous solution extracted with ether. The ether extracts were dried and the solvent was removed under reduced pressure to yield a liquid which, on distillation, gave the desired product having a b.p. 835C at 0.3 mm Hg.

Analysis C 70.3; H 8.1% C 70.7; H 81% Calculated for C H O Found Following a procedure similar to that of Example VIII the following compounds were also prepared:

4-methyl-4-phenoxymethyl-2-phenyl-l ,3-dioxolane (n f 1.5393) Analysis Calculated for C H O Found EXAMPLE X Herbicidal Activity To evaluate their herbicidal activity, the compounds of the invention were tested using as a representative range of plants:

maize, Zea mays (Mz); oat, Avena sativa (O);

rye grass, Lolium perenne (RG); pea, Pisum sativum linseed, Linum usitatissium (L); mustard, Sinapis alba (M);

and sugar beet. Beta vulgaris (SB).

The test fall into two categories, pre-emergence and post-emergence. The pre-emergence tests involved spraying a liquid formulation of the compound onto the soil in which the seeds of the plant species mentioned above had recently been sown. The post-emergence tests involved two types of test, viz, soil drench and foliar spray tests. In the soil drench tests the soil in which seedling plants of the above species were growing was drenched with a liquid formulation containing a compound of the invention, and in the foliar spray tests the seedling plants were sprayed with such a formulation.

The soil used in the tests was a steam-sterilized, modified John Innes Compost mixture in which half the peat, by loose bulk, had been replaced by vermiculite.

The formulations used in the tests were prepared by diluting with water and solutions of the compounds in acetone containing 0.4% by weight of an alkylphenol- /ethylene oxide condensate available under the trade name Triton X-l55. In the soil spray and foliar spray tests the acetone solutions were diluted with an equal l0 cates a reduction in fresh weight of stem and leaf of the plants of approximately 25%, a rating 5 indicates a re- The results of the tests are set out in Table 3. in the tests on certain of the compounds oat was replaced by rice. Orysa saliva (R) and rye grass was re- Post-Emergence (Plants) Pre-Emergence (Seeds) Soil Drench Foliar Spray Soil Spray MZORGPLMSB MzORGPLMSB MzORGPLMSB Compound volume of water and the resulting formulations applied at two dosage levels corresponding to 11.2 and Li pounds of active material per acre, respectively. in the soil drench tests one volume of the acetone solution was diluted to 155 volumes with water and the resulting 5 formulation applied at one dosage level equivalent to I I2 pounds of active material per acre.

in the pre-emergence tests untreated sown soil and in the post-emergencetests untreated soil bearing seed- 4-benzyloxymethyl-2,2.4-trimethyl l.3-dioxolane I 90804M8080949470uh060 8 949 8 929 9272839050 8 8 8 7 7 7 7 63727060 0 20400 60 0303 02020 0 05050 0 0 0 405040 40 4060 0 020705 606062 40 8 932 02086638030 2 l 2 4000000 i 8660500 5 7550000 I: i 2 000 a 00 i 3000000 0000000 i 8540542 it i 7 7 704 20 11 l 7 s s 04 1 0 l l s 2 s 0000 4-(4chlorobenzyloxymethyl)-2,2,4- trimelhyl-l ,Il-dioxolane 4-benzyloxymethyl-4-n-propyl-2.2- dimethyl-l .3-dioxolane 4-benzyloxymethyi-2-isobutyl-2.4- dirnethyl-l .B-dioxolane 4-(4'-methylbenzyloxymethyl )-2,2.4- trimethyll .3-dioxolane 4-(3 'methylbenzyloxymethyl 2.2,4- trimethyll ,3-dioxolane 4-( 3 '.4'-dichlorobenzyloxymethyl)- 2.2.4-trimethyl-l .3diox0lane 4-benzyloxymethyl)-4-ethyl2.2-dimethyll.3-dioxolane 4-benzyloxymeth yl-4-methyl-2-phenyl- I .3-dioxolane 4-benzyloxymethyl-2cthyl-2.4-

dimethyl' I .3-dioxolane 4-benzyloxymethyl-2,4-dimethyl-2-phenyl -l ,3-dioxolane Post-Emergence (Plants) Pre-Emergence (Seeds) Soil Drench Foliar Spray Soil Spray MzRBGPLMSB MzRBGPLMSB MZRBGPLMSB Table 4 Dosage ib/A Compound 4-(4'-fluoro benzyloxymethyl)-2.2.4- trimethyl-l ,S-dioxolane 4-benzyloxymethyl -2.2,4-trimethyl- 1.3-dioxolane 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 6 0 0 4 0 6 4 l 4 4 0 0 0 7 0 0 3 0 0 5 l I 3 0 S 2 J2 ll 2ll llllllllllllllL dimethyl-l .B-dioxolane 4-benzyloxymethyl-Lmethyll .3- dioxolane-Z-spir0cyclopentane 4-benzyloxymethybbmethyll .3- dioxolane 4-benzyloxymethyl-2,4-dimethyl l.3-dioxolane JOSMSO 836560 I 2 l 0 6 O 4-phenoxymelhyl-4-methyl-2-phenyl -l ,3diox0lane 4-benzyloxymethyi-tmethyb2- (2-phenylethyl I ,3-dioxolane d-benzyloxymethyl-4-methyl-1.3- dioxoIane-Z-spir0cyclopentane EXAMPLE Xl Fungicidal Activity The fungicidal activity of the compounds of the invention was tested as follows:

'ling plants were used as controls.

The herbicidal effects of the compounds were assessed visually seven days after spraying the foliage and drenching the soil and eleven days after spraying the soil, and were recorded on a 0-9 scale. A rating 0 indicates no effect on the treated plants, a rating 2 indilntact leaves or leaf pieces of vine, potato and wheat were supported on water-saturated seed germination pads in 9cm petri dishes and were sprayed with aqueous suspensions containing I000 ppm of the test compound. The leaves or leaf pieces were allowed to dry and were then inoculated with spores of Plasmopara vilicola (vine downy mildew). Phyrophrhora infestans (potato late blight) and Puccina recondim (brown wheat rust), respectively. Observations on the development of disease symptoms were made after 2-7 days.

The results of the tests are shown in Table 5 in which a result 2 indicates more than 80% control of the fungal disease. a result I indicates 50-80% control and a result indicates less than 50% control.

12 ring by from I to 3 atoms of chlorine or fluorine or by a lower alkyl group or by a phenyl group.

2. A compound according to claim I wherein R is methyl or ethyl; R and R each is methyl or hydrogen and Y is benzyl optionally substituted by from I to 3 chlorine atoms.

3. A compound according to claim 2 wherein R and R are methyl, R is hydrogen and Y; is benzyl optionally substituted by from i to 3 chlorine atoms.

4. A compound according to claim 2 wherein R is ethyl. R, and R are methyl and Y is benzyl optionally substituted by l to 3 chlorine atoms.

5. A compound of the formula Table Compound Fungicidal Activity P.viticola Pjnfestans P.rocondita 4-benzyloxymethyl-2.2.4-trimethyl-l .3- I 0 0 dioxolane 4-benzyloxymethyl-4-methyl-2-phenyl- 2 2 0 I .3-dioxolane 4-benzyloxymethyl-4-methyll ,3- 2 2 0 dioxolane-2-spirocyclohexanc 4-benzyloxyrnethyll-methyl-l.3- 0 l O dioxolane-Z-spirocyclopentane CH -O CH,- We claim: R g O/C\CH (5",). l. A compound of the formula H,-Obenzyl wherein R is an alkyl group of l to 6 carbon atoms; R and R each is hydrogen, a lower alkyl group, a lower alkyl group substituted by phenyl or a phenyl group optionally substituted by chlorine or by an alkyl group, or R and R together may be a polymethylene group of 3 to 6 carbon atoms; and Y, is a phenyl group, a chlorophenyl group, or benzyl optionally substituted on the 

1. A COMPOUND OF THE FORMULA
 2. A compound according to claim 1 wherein R is methyl or ethyl; R1 and R2 each is methyl or hydrogen and Y3 is benzyl optionally substituted by from 1 to 3 chlorine atoms.
 3. A compound according to claim 2 wherein R and R1 are methyl, R2 is hydrogen and Y3 is benzyl optionally substituted by from 1 to 3 chlorine atoms.
 4. A compound according to claim 2 wherein R is ethyl, R1 and R2 are methyl and Y3 is benzyl optionally substituted by 1 to 3 chlorine atoms.
 5. A compound of the formula
 6. A compound according to claim 5 wherein R is methyl.
 7. A compound according to claim 5 wherein R is ethyl and n is
 4. 8. A compound according to claim 5 wherein R is propyl and n is
 2. 9. 4-benzyloxymethyl-4-methyl-1,3-dioxolane-2-spirocyclohexane. 